This invention relates to sound sources and more particularly to an apparatus for producing a wide band of intensified sound having controllable dispersion characteristics.
In order to produce voice and music sound in large areas, various techniques are employed for generating a high ratio of direct to reflected sound. One technique is to employ a large cluster of speakers having individual drives at a central location, with two locations being used to create stereophonic effects. Another technique is to use multiple locations, with phase delays to the outlying speakers. The latter approach usually results in the generation of large quantities of reflected sound. The use of single locations, while being preferred, requires the use of a large number of relatively expensive individual speakers. Also, the dispersion characteristics to the individual speakers must be taken into consideration to obtain uniform coverage, and this is not always easily accomplished. The individual speakers interfere with each other because their acoustic inputs combine at a point where they are physically too large. As a result, the radiation pattern is distorted or uneven, even though the sound pressure levels are adequate to cover the area.